Substrate processing apparatuses include plasma processing apparatuses that execute processing such as film formation and etching by using specific types of gases on substrates such as semiconductor wafers (hereafter may be referred to simply as “wafers”) placed inside processing chambers or clean the inside of the processing chambers with a specific type of gas.
The discharge gas discharged from a processing chamber of such a substrate processing apparatus may be toxic or may contain a substance that places a heavy burden on the environment. Thus, it would be detrimental to the environment to directly release the discharge gas into the atmosphere. This issue is addressed in some substrate processing apparatuses by releasing the discharge gas from a processing chamber via a scrubbing device that scrubs (eliminates noxious elements in) the discharge gas through a heat treatment or the like.
For instance, the substrate processing apparatus shown in FIG. 24 includes scrubbing devices 20A and 20B respectively provided in conjunction with processing chambers 10A and 10B. In this substrate processing apparatus, the scrubbing devices 20A and 20B respectively connected with discharge systems 12A and 12B for the individual processing chambers 10A and 10B scrub the discharge gas from the processing chambers 10A and 10B. This type of substrate processing apparatus, which requires as many scrubbing devices as processing chambers, is bound to take up a large installation space and its manufacturing costs are bound to be high.
These problems are addressed by adopting a structure such as that shown in FIG. 25, which includes a common discharge system 31 connected with discharge systems 12A and 12B of the individual processing chambers 10A and 10B, with the common discharge system 31 connected with a scrubbing device 30 to serve both the processing chambers 10A and 10B so as to scrub the discharge gas from the processing chambers 10A and 10B through a single scrubbing device 30 (see, for instance, Japanese Laid Open Patent Publication No. H11-8200 and Japanese Laid Open Patent Publication No. 2004-95643).